parallax adjustments vs. none?
 

im looking to buy the nikon's p-223 3-9x40 or the m-223 3-12x42 bdc for my AR 15.. The m-223 has side parallax adjustment, is it necessary to have this, or i should ask whats the advantages and disadvantages? I pretty much just do target shooting and hunt coyotes

You do not ever "need" parallax adjustment. You are likely to be more accurate with it though. But each scope is parallax free at a certain set distance, if you shoot at that distance parallax adjustment would do you no good. My guess would be at least 75% of shooters that have parallax adjustment on their scopes never use it. Your scope specs should say the parallax free distance.

Now its my understanding that the parallax adjustment is the yard adjustment turret 50,100,200 and so forth or am I not understanding it correctly

Your parallax is basically you not being on the same focal plane as your target. Most non PA or AO scopes are set to 100 yards. Mostly it doesn't make a lot of difference unless it really up close like 50 yards or a long ways off like 500 yards. I have it on all my scopes, once you get used to it you will like it better. I prefer it on the turret with the other dials, not out on the end of the scope. That way you don't have to get off your gun to adjust it, just open your other eye.

Ok so with that being said the m223 would probably be better instead of the p223 that doesnt have that?

I have no idea what either of those are.

I wish I had gotten the model scope that allows for parallax adjustment. Mine does not, therefore I need to be careful to put my cheek on the exact same spot on the rifle butt each time. You can work around not having a parallax adjustment, but it is nice to have it.

Ergo it is worth the extra few bucks.

I think the term parallax adjustment is confusing or not correct.

It's really a focus knob and by setting the focus correctly you eliminate parallax error (seeing two images).

Is this correct?

For all practical purposes, yes.

If you're an expert rifleman, and good at doping wind, mirage, and measuring range with a laser, it can be a very good addition. For the average shooter, it's like a spoiler on a Chevy Volt. Looks "Kewl" but doesn't do much for you.

OTOH, it most certainly won't hurt anything, so if you want it, then get it!:D

@ model70 Nikon makes m 223 & p223 basically for the ar platform calibrated for .223 bdc